//
// "$Id: Fl_PNM_Image.cxx 9709 2012-11-09 16:02:08Z manolo $"
//
// Fl_PNM_Image routines.
//
// Copyright 1997-2010 by Easy Software Products.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     http://www.fltk.org/COPYING.php
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//
// Contents:

//
//   Fl_PNM_Image::Fl_PNM_Image() - Load a PNM image...
//

//
// Include necessary header files...
//

#include "Fl.H"
#include "Fl_PNM_Image.H"
#include <stdio.h>
#include <stdlib.h>
#include "fl_utf8.h"
#include "flstring.h"


//
// 'Fl_PNM_Image::Fl_PNM_Image()' - Load a PNM image...
//

/**
 The constructor loads the named PNM image.

 The destructor frees all memory and server resources that are used by
 the image.

 Use Fl_Image::fail() to check if Fl_PNM_Image failed to load. fail() returns
 ERR_FILE_ACCESS if the file could not be opened or read, ERR_FORMAT if the
 PNM format could not be decoded, and ERR_NO_IMAGE if the image could not
 be loaded for another reason.
 */
Fl_PNM_Image::Fl_PNM_Image(const char *name)	// I - File to read
	: Fl_RGB_Image(0,0,0)
{
	FILE		*fp;		// File pointer
	int		x, y;		// Looping vars
	char		line[1024],	// Input line
	             *lineptr;	// Pointer in line
	uchar		*ptr,		// Pointer to pixel values
	             byte,		// Byte from file
	             bit;		// Bit in pixel
	int		format,		// Format of PNM file
	             val,		// Pixel value
	             maxval;		// Maximum pixel value


	if ((fp = fl_fopen(name, "rb")) == NULL) {
		ld(ERR_FILE_ACCESS);
		return;
	}

	//
	// Read the file header in the format:
	//
	//   Pformat
	//   # comment1
	//   # comment2
	//   ...
	//   # commentN
	//   width
	//   height
	//   max sample
	//

	lineptr = fgets(line, sizeof(line), fp);
	if (!lineptr) {
		fclose(fp);
		Fl::error("Early end-of-file in PNM file \"%s\"!", name);
		ld(ERR_FILE_ACCESS);
		return;
	}

	lineptr ++;

	format = atoi(lineptr);
	while (isdigit(*lineptr)) lineptr ++;

	if (format == 7) lineptr = (char *)"";

	while (lineptr != NULL && w() == 0) {
		if (*lineptr == '\0' || *lineptr == '#') {
			lineptr = fgets(line, sizeof(line), fp);
		} else if (isdigit(*lineptr)) {
			w(strtol(lineptr, &lineptr, 10));
		} else lineptr ++;
	}

	while (lineptr != NULL && h() == 0) {
		if (*lineptr == '\0' || *lineptr == '#') {
			lineptr = fgets(line, sizeof(line), fp);
		} else if (isdigit(*lineptr)) {
			h(strtol(lineptr, &lineptr, 10));
		} else lineptr ++;
	}

	if (format != 1 && format != 4) {
		maxval = 0;

		while (lineptr != NULL && maxval == 0) {
			if (*lineptr == '\0' || *lineptr == '#') {
				lineptr = fgets(line, sizeof(line), fp);
			} else if (isdigit(*lineptr)) {
				maxval = strtol(lineptr, &lineptr, 10);
			} else lineptr ++;
		}
	} else maxval = 1;

	// Allocate memory...
	if (format == 1 || format == 2 || format == 4 || format == 5) d(1);
	else d(3);

//  printf("%s = %dx%dx%d\n", name, w(), h(), d());

	if (((size_t)w()) * h() * d() > max_size() ) {
		Fl::warning("PNM file \"%s\" is too large!\n", name);
		fclose(fp);
		w(0);
		h(0);
		d(0);
		ld(ERR_FORMAT);
		return;
	}
	array       = new uchar[w() * h() * d()];
	alloc_array = 1;

	// Read the image file...
	for (y = 0; y < h(); y ++) {
		ptr = (uchar *)array + y * w() * d();

		switch (format) {
		case 1 :
			for (x = w(); x > 0; x --)
				if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * (1-val));
			break;

		case 2 :
			for (x = w(); x > 0; x --)
				if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
			break;

		case 3 :
			for (x = w(); x > 0; x --) {
				if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
				if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
				if (fscanf(fp, "%d", &val) == 1) *ptr++ = (uchar)(255 * val / maxval);
			}
			break;

		case 4 :
			for (x = w(), byte = (uchar)getc(fp), bit = 128; x > 0; x --) {
				if ((byte & bit) == 0) *ptr++ = 255; // 0 bit for white pixel
				else *ptr++ = 0; // 1 bit for black pixel

				if (bit > 1) bit >>= 1;
				else {
					bit  = 128;
					if (x > 1) byte = (uchar)getc(fp);
				}
			}
			break;

		case 5 :
		case 6 :
			if (maxval < 256) {
				if (fread(ptr, w(), d(), fp)) {
					/* ignored */
				}
			} else {
				for (x = d() * w(); x > 0; x --) {
					val = (uchar)getc(fp);
					val = (val<<8)|(uchar)getc(fp);
					*ptr++ = (255*val)/maxval;
				}
			}
			break;

		case 7 : /* XV 3:3:2 thumbnail format */
			for (x = w(); x > 0; x --) {
				byte = (uchar)getc(fp);

				*ptr++ = (uchar)(255 * ((byte >> 5) & 7) / 7);
				*ptr++ = (uchar)(255 * ((byte >> 2) & 7) / 7);
				*ptr++ = (uchar)(255 * (byte & 3) / 3);
			}
			break;
		}
	}

	fclose(fp);
}


//
// End of "$Id: Fl_PNM_Image.cxx 9709 2012-11-09 16:02:08Z manolo $".
//
